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Thread: Seeking advice on the round circles in the middle of the photos

  1. #1
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    Default Seeking advice on the round circles in the middle of the photos

    Recently I went to Iceland and managed to capture northern lights. I realised that some/most photos having uniform round circles in the middle of the photos.
    Anyone knows what causes it?

    https://goo.gl/photos/4PzkGWyWWEDNy6sr6

    I am using canon 550d and tamron 17-55 lens.

  2. #2
    Senior Member shierwin's Avatar
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    Default Re: Seeking advice on the round circles in the middle of the photos

    Are these white dots in the same position in most of the images? May be stars Let hear the views of the experts here

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    Default Re: Seeking advice on the round circles in the middle of the photos

    bro, if I'm not wrong, that happens is because it's out of focus....
    Too many great equipments but too little quality photos. [My Flickr] | [My Blog]

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    Default Re: Seeking advice on the round circles in the middle of the photos

    It seems to happen on the same spot for my photos. I used manual focus.

    I don't see such circles for the photos taken in the day.

  5. #5

    Default Re: Seeking advice on the round circles in the middle of the photos

    First thought is that those look like overexposed stars? What was the exposure time?

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    Default Re: Seeking advice on the round circles in the middle of the photos

    25 or 30 seconds.

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    Senior Member shierwin's Avatar
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    Default Re: Seeking advice on the round circles in the middle of the photos

    Quote Originally Posted by kiattan View Post
    It seems to happen on the same spot for my photos. I used manual focus.

    I don't see such circles for the photos taken in the day.
    Quote Originally Posted by kandinsky View Post
    First thought is that those look like overexposed stars? What was the exposure time?
    Quote Originally Posted by kiattan View Post
    25 or 30 seconds.
    These replies explain clearly the occurrence of "white circles"

  8. #8
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    Default Re: Seeking advice on the round circles in the middle of the photos

    Quote Originally Posted by kiattan View Post
    It seems to happen on the same spot for my photos. I used manual focus.

    I don't see such circles for the photos taken in the day.
    ***Not sure if your question is about OOF or not... sry if I misinterpret ur question.

    Since you mentioned manual focus, I suspect that there might be some form of mis-focus (especially during night where focusing becomes tough under such situation and 10x magnification isn't usable). From my past shoot, so long if I misfocus abit, those stars will turn round (OOF). If those at the edges or other parts of the lens is not rounded, then the lens element is probably shifted/tilted internally where it causes focus to be different.
    Last edited by SkyStrike; 13th October 2015 at 03:28 PM.
    Too many great equipments but too little quality photos. [My Flickr] | [My Blog]

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    Default Re: Seeking advice on the round circles in the middle of the photos

    The circles always centered in the center of the photos. Hence I am skeptical about mis focus? Maybe I am wrong too. Quite a newbie in photography.

    Later I can post more photos to better illustrate my points. Thanks all for the reply so far

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    Default Re: Seeking advice on the round circles in the middle of the photos

    More photos. All with rings of circles in the center. Need to zoom in into the center to see it. Regardless portrait or landscape.
    https://goo.gl/photos/4PzkGWyWWEDNy6sr6
    https://goo.gl/photos/xDQx1Wd7e457ig5T7
    https://goo.gl/photos/7xHvzF4Hff2NmHJ18

  11. #11

    Default Re: Seeking advice on the round circles in the middle of the photos

    I saw the rings. Very faint rings in the middle of the photos. Only when you zoom in all the way in the center of the photos.
    Quite weird. Never saw anything like this before.

    Have you took the northern lights with other lens?

  12. #12

    Default Re: Seeking advice on the round circles in the middle of the photos

    Quote Originally Posted by kiattan View Post
    More photos. All with rings of circles in the center. Need to zoom in into the center to see it. Regardless portrait or landscape.
    https://goo.gl/photos/4PzkGWyWWEDNy6sr6
    https://goo.gl/photos/xDQx1Wd7e457ig5T7
    https://goo.gl/photos/7xHvzF4Hff2NmHJ18
    OH! I get what you're referring to now... you're not referring to the blown out circle dots but something else.

    Here's a screenshot for those who haven't noticed it yet.



    -------------

    Did you have a UV filter on? Found a pretty cheem explanation:

    With my Nikon lenses I have found that long exposures result in concentric circles showing up in the center of the images when I use a filter of any kind. Nikon says this is due to the high reflectivity of the aurora.

    Thanks to the University of Alaska forecaster, Chuck Deehr, the explanation follows. "These are interference fringes due to the parallel faces of the filter and to the narrow spectral emission at 5577 Angstroms in the aurora. That green, atomic oxygen emission line is the strongest emission in the aurora near our film and eye peak sensitivity, so it shows up first when there is any device in the optical path which sorts out the spectral emissions." So, don't use filters!

    http://www.eaglestation.com/dick/aurora.html
    When I looked closely at the center of the pictures (at least in the original unscaled versions), I could see concentric rings. When I first saw them, I found them to be quite strange, but interesting nevertheless.

    At first, I thought they were Airy rings, but after thinking for a while, I realized that there is no small aperture from which they could arise. After some more thought, I found the solution - they are interference rings from somewhere in the optics. My suspicion fell on the UV filter I bought for my lens, a suspicion which was confirmed once I photographed another aurora without the filter.

    So, where does this interference pattern come from, and what can we learn from it?

    The first thing to note, is that the fact that there is an interference pattern, implies that the light is monochromatic, or at least coming from a very narrow wave band. Since I can count at least 30 rings, the waveband should be no more than about 1/30 of the wavelength. Since green is about 5500, the emitted waveband has to be narrower than about 200. In fact, the radiation is monochromatic. It comes from a well known 5577 forbidden line of Oxygen, namely, under lab conditions, they cannot be observed.

    http://www.sciencebits.com/auroras
    Last edited by kandinsky; 13th October 2015 at 04:43 PM.

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    Default Re: Seeking advice on the round circles in the middle of the photos

    Wow. Thanks for the explanation. I tried googling but can't get any answers.

    The explanation is indeed chim. And yes! I am using UV filter. It's so sad!! Chance upon northern lights and the photos turned out with the rings of circles


    Quote Originally Posted by kandinsky View Post
    OH! I get what you're referring to now... you're not referring to the blown out circle dots but something else.

    Here's a screenshot for those who haven't noticed it yet.



    -------------

    Did you have a UV filter on? Found a pretty cheem explanation:

  14. #14

    Default Re: Seeking advice on the round circles in the middle of the photos

    Good information. Will take off UV filter if I ever go see northern light!

  15. #15

    Default Re: Seeking advice on the round circles in the middle of the photos

    One question. Does the northern light look that saturated as in the photo in real life or is the photo processed to increase saturation.

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    Default Re: Seeking advice on the round circles in the middle of the photos

    The photos that I have posted have not been processed. I captured in jpeg and raw. The photos uploaded to Google is jpeg.



    Quote Originally Posted by DSolZ View Post
    One question. Does the northern light look that saturated as in the photo in real life or is the photo processed to increase saturation.

  17. #17

    Default Re: Seeking advice on the round circles in the middle of the photos

    Saw this article
    https://luminous-landscape.com/auror...camera-sensors
    hence got curious. Thanks for the information.

  18. #18
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    Default Re: Seeking advice on the round circles in the middle of the photos

    I read the articles. I was lucky to see aurora with my naked eyes and it was dancing and brightly lit.





    Quote Originally Posted by DSolZ View Post
    Saw this article
    https://luminous-landscape.com/auror...camera-sensors
    hence got curious. Thanks for the information.

  19. #19

    Default Re: Seeking advice on the round circles in the middle of the photos

    Quote Originally Posted by kiattan View Post
    I read the articles. I was lucky to see aurora with my naked eyes and it was dancing and brightly lit.
    Really lucky. Money well spent.

  20. #20

    Default Re: Seeking advice on the round circles in the middle of the photos

    Nice shots nevertheless bro!

    One day you'll look back and know how this experience has helped to improve your photography in some way. hahaha. Everyone learns from their past mistakes.

    Hope I get some luck to see them in the future

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